Dialysis water system



Sept. 15, 1970 c. CAPPELEN, JR 3,

' DIALYSIS WATER SYSTEM Filed June 27, 1968 3 v 1 1- W (9 L145 ifi.

. 20 c KID I 19 .k-/ 17 1'5 United States Patent 3,528,550 DIALYSISWATER SYSTEM Christian Cappelen, Jr., Oslo, Norway, assignor to A/SNycotron, Oslo, Norway Filed June 27, 1968, Ser. No. 740,541 Claimspriority, applica6tion Norway, July 4, 1967,

Int. Cl. B01d13/o0, 31/00 US. Cl. 210-180 2 Claims ABSTRACT OF THEDISCLOSURE removed.

The present invention relates to a dialysis water system, for theproduction of dialysis liquid for use in dialysis apparatus for thetreatment, in hospital or domestically, of patients sutfering fromcronic or acute nephralgia.

In so called artificial kidneys, the blood of the patient is passed in avery thin layer between two diaphragms which, on the opposite side arebathed with a dialysis liquid, a dialysis taking place through thediaphragms, the blood thereby emitting such substances which areaccumulated during urine poisoning, at the same time as a correction istaking place of the liquid and electrolyte disarrangements which mightbe present in the blood system. The diaphragms are therefore passingsubstances in both directions. Consequently, it is of the greatestimportance that the composition of the dialysis liquid be correct, andin particular it is of importance that it does not contain any air.Obviously, the arrangement of the diaphragms with intermediary layers ofblood, and flushed by dialysis liquid may be multiplied, when required.

If, by way of example, it is presumed that a dialyzer having four bloodlayers is used, it may contain about 50 ml. blood, which for the purposeof a satisfactory dialysis would need a very great quanttiy of dialysisliquid, upwards to several hundred liters. Even if it might be possibleto produce a satisfactory liquid in a thermostatically controlled tank,obviously a series of practical circumstances are prevailing whichdictate a continuous production of dialysis liquid, on the basis of aconcentrate which is admixed with tap water, in correct proportion andat the correct temperature.

The present invention relates to a system for the production of dialysisliquid, a system which may be adapted to a simple dialysis apparatus,for the personal use of the patient, or for attachment to a number ofsuch apparatus, for use in hospitals, and the object of the invention inparticular is to ensure that the dialysis liquid is air free whenentering the dialysis apparatus proper.

According to the invention this is achieved by passing the dialysisliquid, upon having been passed through the dialysis apparatus and thenthrough a venturi device which, by means of a conduit, is connected to adegassing device for the liquid, positioned upstream of the dialysisapparatus. As, the dialysis liquid is pumped through the 3,528,550Patented Sept. 15, 1970 dialysis apparatus, the liquid flow will, as ina water jet pump, draw air from the degassing device so that the liquidwhen arriving at the dialysis apparatus will be air and gas free, andthere wil be no danger of gas diffusion through the diaphragms of theapparatus.

In accordance with the invention, such an air suction arrangement isincluded in a dialysis liquid system, which is adapted to be connectedto a dialysis apparatus having diffusion in layers between blood andliquid, and a characteristic feature of this system is that the samecomprises a degassing tank through which conveniently temperate tapwater is carried before being admixed to dialysis liquid concentrate.

In accordance with a further feature of the invention, the passage ofthe idalysis liquid through the dialysis apparatus is ensured by meansof a suction pump which is arranged at the downstream side of thedialysis apparatus and which draws liquid from a tank which is arrangedon the upstream side of the apparatus, through a choke and stop valve.

The accompanying drawing schematically illustrates a systemincorporating the present invention In the drawing, 1 is a water tapconnection, while 2 is a reduction valve for controlling the pressure ofthe water introduced into the system. Though not shown in the drawing,fiilter devices may be incorporated upstream of the valve 2.

From the valve 2, the Water is fed in two parallel runs, one to aheating device 3 and then to a thermostatically controlled mixing valve4 and the other directly to thermostatically controlled mixing valve 4wherein the temperature of the water leaving this valve is set to bodytemperature, or slightly above the same, in view of later heat lossesbefore the water arrives in the dialysis apparatus proper.

'From the mixing valve 4, the water is fed to a degassing device 5, inwhich air, which might be contained in the water, is removed, andfurther to a suction pump 6, the pressure side of which is connected toa venturi device 7, which through a conduit 8 including a stop valve 9,draws dialysis liquid concentrate from the storage tank 10 and mixeswater and concentrate thereby forming a liquid of physiologicallycorrect concentration.

The dialysis liquid so prepared is fed to a tank 11, provided with anoverflow 12 and a choke valve 13, and is thence delivered to thedialysis apparatus proper, which in the drawing is only indicated at 14with its connection points 15. The delivery from the tank 11 and thepassing through the dialysis apparatus is secured by a suction pump 16,which is arranged at the downstream side of the apparatus. At thesuction side of the pump 16, a venturi device 17 is mounted which,through a conduit 18 is connected to the degassing device 5, so that thelatter is always subjected to a vacuum so that all air which might becontained in the water supply is drawn out by means of the flow ofdialysis liquid after it has performed its function in the dialysisapparatus. From the venturi device 17, the liquid, together with thegases absorbed by the same, is carried through the pump 16 to the drain19. The overflow 12 of the tank 11 is connected by conduit 20 to theliquid with absorbed gases flowing into pump 16.

Without being indicated in the drawing the system obviously is providedwith control and supervision instruments, in particular for temperature,pressure and concentration, which are the essential parameters of a safeperformance of the system so that the valve 13 and thereby theconnection to the dialysis apparatus is automatically and momentarilyclosed at any deviation from predetermined marginal values of theessential Parameters.

I claim:

1. Apparatus for use with artificial kidney machines for obtaininggas-free dialysis liquid for use in said artificial kidney machineswhich operate on the dialysis principle comprising inlet and dischargecondiut means connected to said artificial kidney for feeding freshdialysis liquid to said artificial kidney machine and discharging useddialysis liquid from said artificial kidney machine, respectively aventuri connected to said discharge conduit means, a degassing deviceconnected to said inlet conduit means and a suction conduit connectingsaid venturi to said degassing device, whereby used dialysis liquidpassing through said venturi causes a vacuum to be References CitedUNITED STATES PATENTS 10/1968 Willock 210-321 X 4/1969 Serfass et a1.210--321 XR REUBEN FRIEDMAN, Primary Examiner R. A. SPEAR, ]R.,Assistant Examiner US. Cl. X.R.

